[A patient suffering from priapism as a side-effect of pipamperone]

Antipsychotic drugs can cause a wide and varied range of side -effects because of their affinity for serotonergic, dopaminergic, adrenergic and histaminergic receptors. Priapism is a rare and serious side-effect of antipsychotic drugs and is probably caused by their alpha 1-adrenergic receptor blocking activity.

A 13-year-old boy with a history of Gilles de la Tourette Syndrome was presented to the urologist with a history of a penile erection for more than 24 hours, since waking the previous morning. He had used pipamperone and clonidine for a long period of time and he reported that he regularly had prolonged erections since one year. An ischaemic priapism was diagnosed. Underlying pathology as the cause of the priapism was ruled out and the diagnosis of pipamperone-induced priapism was made per exclusionem.

The use of antipsychotic drugs should be discontinued in the occurrence of this side-effect. If necessary, an alternative drug with a low alpha 1-adrenergic receptor affinity should be given.